The present invention relates generally to temperature control devices, and more particularly to an anticyclone powered active thermal control unit to control the temperature of an apparatus, such as an integrated heat spreader on a high-powered microprocessor or other device.
Electronic devices and circuits are being required to perform more functions at ever increasing speeds. At the same time component densities are increasing while packaging size requirements are decreasing. The higher component densities, higher operating frequencies and tighter packaging requirements are resulting in the generation of excessive heat that must be managed for proper operation and longevity of today""s high performance electronic devices and circuits.
Additionally, in some circumstances it may be desirable to test electronic circuits and devices to determine how they will operate under temperature extremes. Subjecting these devices to such conditions can serve to identify defective components that will fail under extreme hot or cold conditions. Extreme temperature testing may also serve to identify redesign requirements to make the device more robust.
A known device for use in controlling the temperature of a high-performance, high-powered device, such as a microprocessor or the like, for either heat management or testing, is a thermal control unit typical of that shown in FIG. 1. The thermal control unit 100 includes a two-dimensional control structure 102. Thermoelectric modules 104 are disposed on the control structure 102 and may be thermally coupled to the control structure 102 by a layer of thermal interface material 106. A heat exchanger 108 is disposed over the thermoelectric modules 104 and may also be thermally coupled to the thermoelectric modules 104 by another layer of thermal interface material 110. A temperature sensor 112 in the control structure 102 thermally contacts the device 114 under test or device whose temperature is to be controlled by the thermal control unit 100 and provides a signal representative of a temperature of the device 114 to a temperature controller (not shown). The temperature controller then regulates the current flow through the thermoelectric modules 104 to heat or cool the control structure 102 and consequently control the temperature of the device 114.
As evident from FIG. 1, the thermal control unit 100 only has the ability to transfer heat flux (Watts/m2) in two dimensions through the planar control structure 102. Thermoelectric modules 104 can be added in an array arrangement which may improve the total heat transfer abilities of the unit 100 but will not drastically improve the unit""s ability to control large heat fluxes.
Another way current thermal control units 100 deal with large heat fluxes is to increase the surface area of control structure 102 so that more thermoelectric modules 104 or larger thermoelectric modules 104 can be placed on the two dimensional planar control structure 102. This, however, requires a proportionate increase in the surface area of the device 114 under test through which heat flux can be transferred.
Another problem presented by increasing the number of thermoelectric modules 104 is the increase in power and control wiring. Most thermal control units 100 now contain at least four thermoelectric modules 104 to manage the higher heat transfer demands during testing. This results in a minimum of eight large power wires connected together internally within the thermal control unit 100. These wires also need to be strain relieved, resulting in a complex assembly process. Solder joints can also fatigue and break if not properly strain relieved or if poor solder techniques are employed, thus resulting in reduced reliability of the thermal control unit 100. Additionally the temperature sensor 112 or resistive temperature device used to sense the temperature of the device 114 under test for temperature control purposes typically utilizes very fragile wires, which are most often smaller than 30 gauge. Accordingly, these wires may also be broken if care is not taken during assembly of the thermal control unit 100, necessitating that the unit 100 be disassembled and the wiring repaired.
Another issue with current thermal control units 100 is that the thermoelectric modules 104 are made of a ceramic material and are very sensitive to non-uniform loading that can cause cracking resulting in expensive repairs and downtime of the test equipment. Additionally, the two-dimensional array arrangement of thermoelectric modules 104 of current thermal control units 100 cause the forces resulting from actuation of the device 114 under test to be applied through the thermoelectric modules 104. This results in an additional fatigue mechanism being applied to the thermoelectric modules 104 that can shorten their useful life. The non-uniform loading and the actuation of the thermal control unit 100 onto the device 114 under test will cause fatigue loading that can also result in the thermal interface film or material 106 and 110 breaking down and weeping from the thermoelectric modules 104, heat exchanger 108 and the control structure 102.
Accordingly, for the reasons stated above, and for other reasons that will become apparent upon reading and understanding the present specification, there is a need for a thermal control unit that has the ability to regulate large heat fluxes, addresses power and control wiring management problems, and uneven loading of thermoelectric modules to improve unit reliability and longevity. Additionally, there is also a need for a thermal control unit that can easily be adapted to any type test equipment, such as product platform validation (PPV) test equipment or the like.